My previous patents which relate to the present invention include U.S. Pat. No. 4,497,370, Feb. 5, 1985, entitled "Apparatus And Method For Recovery Of Liquid Hydrocarbons From Ground Water," U.S. Pat. No. 4,663,037, May 5, 1987, entitled "Apparatus For Recovery Of Liquid Hydrocarbons From Ground Water," and U.S. Pat. No. 4,761,225, Aug. 2, 1988, entitled "Apparatus For Controlling The Removal Of Liquid Hydrocarbons From Groundwater."